Characteristics of Olfactory Disorders in Relation to Major Causes of Olfactory Loss

ORIGINAL ARTICLE Characteristics of Olfactory Disorders in Relation to Major Causes of Olfactory Loss

Andreas F. P. Temmel, MD; Christian Quint, MD; Bettina Schickinger-Fischer, MD; Ludger Klimek, MD; Elisabeth Stoller; Thomas Hummel, MD

Objective: To investigate the consequences of olfac- younger patients. Regarding changes in quality of life tory loss and explore specific questions related to the effect (QoL), we found that (1) in most patients olfactory loss of duration of olfactory loss, degree of olfactory sensi- caused food-related problems; (2) loss in QoL did not tivity, and cause of the olfactory loss. change with duration of olfactory loss; (3) younger patients had more complaints than older ones, and Patients: A total of 278 consecutive patients with hy- women had more complaints than men; (4) complaint posmia or anosmia were examined. scores were higher in hyposmic patients than in anosmic patients; and (5) self-rated depression did not re- Results: Causes of olfactory loss were categorized as late to measured olfactory function. follows: trauma (17%), upper respiratory tract infection (URI) (39%), sinonasal disease (21%), congenital anos- Conclusions: Among many complaints of olfactory loss, mia (3%), idiopathic causes (18%), or other causes the predominant ones were food related. This loss in QoL (3%). Our data suggest that (1) recovery rate was seemed to be of greater importance in younger than in higher in URI olfactory loss than in olfactory loss from older people, and women seem to be affected more other causes; (2) likelihood of recovery seemed to de- strongly than men. crease with increased duration of olfactory loss; and (3) the elderly are more prone to URI olfactory loss than Arch Otolaryngol Head Neck Surg. 2002;128:635-641

OSS OF olfactory function degree, and causes of the olfactory dis- affects the patient’s appre- order. ciation of food and drink; it has an impact on safety (eg, RESULTS detection of spoiled foods andL smoke); and it may also produce CHARACTERISTICS bodily insecurity: the patient’s own body OF PATIENTS odors are no longer self-perceived, which, in our clinical experience and A total of 278 patients were included that of others,1 has led to an exaggeration (155 women, 123 men). All of them had of patients’ hygiene measures or the olfactory dysfunction as established by excessive use of perfume. However, the means of psychophysical testing; 151 loss of olfaction can be particularly were functionally anosmic, 127 were hy- From the Department of insidious and escape detection because, posmic. Major causes for olfactory loss Otorhinolaryngology, unlike loss of sight or hearing, it is not were upper respiratory tract infection University of Vienna, Austria readily apparent to others. A good (URI) (n=102; 36%), sinonasal disease (Drs Temmel, Quint, and example of this difficulty of detection is (SND) (n=60; 21%), trauma (n=47; Schickinger-Fischer); Deutsche that patients with congenital anosmia in 17%), congenital anosmia (n=9; 3%), Klinik fu¨r Diagnostik, our population did not discover their and other causes including intoxication Wiesbaden (Dr Klimek), and the Department of olfactory loss until after age 10 years. (solvents), abuse of nasal decongestants, Otorhinolaryngology, The present study was designed to inves- Parkinson disease, radiation, or cerebral University of Dresden Medical tigate the consequences of olfactory loss infarction (n=9; 3%). No reason for ol- School, Dresden (Ms Stoller in daily life and to explore specific ques- factory loss could be identified in 51 pa- and Dr Hummel), Germany. tions related to the effect of the duration, tients (18%) (Figure 1); in at least 9 of

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©2002 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/30/2021 PATIENTS, MATERIALS, score between 16 and 30, he or she was considered hyposmic. With a score lower than 16, the patient was re- AND METHODS garded as functionally anosmic.4 Olfactory evaluation re- quired approximately 30 minutes. Diagnostic criteria for the classification of the cause of the olfactory disorder are We evaluated 278 consecutive patients (155 women, 123 given in Table 1. men) with olfactory loss who were either referred or di- rectly sought help for olfactory disorders at the depart- QUESTIONNAIRE ments of otorhinolaryngology of the University of Vienna, Austria, and the University of Dresden, Germany. Sub- A self-reporting questionnaire was used that contained jects were between ages 14 and 86 years. The study was mainly questions regarding olfactory sensitivity and qual- performed according to the principles of the Declaration ity of life (QoL) issues. It had been developed in collabo- of Helsinki/Summerset West on biomedical research in- ration with the Arbeitsgemeinschaft Olfaktologie/ volving human subjects. All patients were thoroughly ex- Gustologie der Deutschen Gesellschaft fu¨ r Hals-Nasen- amined by an experienced otorhinolaryngologist, includ- Ohren Heilkunde, Kopf- und Halschirurgie, Dresden, ing detailed endoscopic investigation of the olfactory Germany. Questions related to the subjective degree of ol- cleft. Whenever a patient’s history was unclear or the psy- factory loss and associated difficulties such as cooking, eat- chophysical olfactory test results were ambiguous, the pa- ing, body hygiene, appetite, problems in everyday life, ways tient additionally underwent computed tomographic to manage this handicap, and the subjective degree of de- scans of the nasal cavity, magnetic resonance imaging crease of QoL. Both affirmative and symptom-based ques- with a special focus on important olfactory structures (eg, tions were used. Questionnaires were filled in before com- olfactory bulbs and tracts, olfactory sulcus), or olfactory mencement of olfactory tests. After receiving detailed evoked potentials.2 instructions by a member of the staff, the subjects usually completed the forms in the waiting area. CHEMOSENSORY TESTING STATISTICAL ANALYSIS Psychophysical testing was performed by means of “Snif- fin’ Sticks”3,4 bilaterally, and it involved tests for odor Statistical analyses were performed using SPSS 10.0 (SPSS threshold (N-butanol), discrimination, and identification. Inc, Chicago, Ill). Data were submitted to nonparametric Results of the 3 subtests were presented as a sum of the statistical analysis including Kruskal-Wallis, Mann- results obtained for threshold, discrimination, and identi- Whitney, and ␹2 tests. Correlational analyses were per- fication measures (TDI score).4 If the TDI score was 31 or formed using Spearman statistics. The minimum ␣ level was higher, the patient was considered normosmic; with a .05. Nonsignificant results are indicated as NS.

these patients who were older than 70 years, aging sex-related differences were not significant for SND (19% might have contributed to olfactory loss.5 women vs 25% men), trauma-related olfactory loss (12% women vs 24% men), or idiopathic olfactory disorders RELATIONSHIP OF TEST SCORES (19% women vs 18% men). Approximately the same por- TO CAUSES OF OLFACTORY LOSS tion of male and female patients suffered from hyposmia and anosmia (women, 73 with hyposmia vs 82 with Results of the 3 different olfactory tests are shown in anosmia; men, 54 with hyposmia vs 69 with anosmia). Table 2, separately for anosmic and hyposmic patients in relation to the investigated causes of olfactory loss. When RELATIONSHIP BETWEEN AGE comparing results of hyposmic patients in the 3 olfactory AND OLFACTORY DISORDER tests, we found no significant difference between the 4 ma- ␹2 Ͻ Ͼ jor causes ( 3 2.3; P .51; Kruskal-Wallis test); in other We categorized subjects into 3 age groups: group A, words, the results pattern from the 3 olfactory tests did younger than 41 years (n=60); group B, 41-60 years not indicate the cause of the disorder. (n=130); and group C, older than 60 years (n=88). Dif- In URI olfactory loss, more patients were found to be ferent causes were present at different ratios in these 3 age hyposmic (n=62) than anosmic (n=40) (␹2=4.75; P=.03). groups. The highest percentage of URI olfactory disor- In contrast, for all other causes, this ratio was reversed (for ders was seen in older subjects (group A, 23%; group B, SND, 28 hyposmic vs 32 anosmic [NS]; trauma, 15 hypos- 31%; and group C, 55%). No such differences were found mic vs 32 anosmic [␹2 = 6.15; P = .01]; idiopathic cases, 18 for SND (A, 30%; B, 24%; and C, 13%), posttraumatic hyposmic vs 33 anosmic [␹2 = 4.41; P= .04]; other causes, causes (A, 20%; B, 18%; and C, 14%), or idiopathic causes 4 hyposmic vs 5 anosmic [NS]). (group A, 15%; B, 22%; and C, 15%) (Figure 2). Statis- tical differences in the relative presence of the 4 most fre- RELATIONSHIP BETWEEN SEX quent causes were found only for group C (␹2=46.38; AND OLFACTORY DISORDER PϽ.001). The relative number of hyposmic patients was not significantly different in different age groups (group A higher percentage of women (44%) than men (28%) A, 31 hyposmic vs 29 anosmic; group B, 56 hyposmic vs suffered from URI olfactory loss (␹2=11.3; P=.001). These 74 anosmic; group C, 40 hyposmic vs 48 anosmic).

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©2002 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/30/2021 Table 1. Categorization of Patients According to History of Their Olfactory Disturbance*

Cause of No. of Olfactory Loss Patients History Olfactory Cleft† Onset Post-URI 102 Prior symptoms of upper respiratory tract inflammation Patent Sudden Posttraumatic 47 Prior head injury, closed or open Patent Sudden SND 60 Chronic rhinitis or sinusitis, anatomical obstruction Patent or obstructed Gradual, fluctuating Idiopathic 51 None of the above Patent Sudden or gradual Congenital 9 Never experienced any odorous sensations Patent Olfactory sensations never present

*URI indicates upper respiratory tract infection; SND, sinonasal disease. †Patency of the olfactory cleft was established by means of endoscopy (and coronary computed tomographic scan, whenever necessary).

RELATIONSHIP BETWEEN Other DURATION OF OLFACTORY DISORDER, Congenital CAUSE, AGE, AND SEX

We categorized subjects into 3 duration groups of olfac- URI Idiopathic tory loss: group A, less than 24 months; group B, 24-48 months; and group C, longer than 48 months. The presence of anosmia increased with duration of olfactory loss. Specifically, most of the patients with the longest duration of olfactory loss were anosmic (group C, 16 hy- ␹2 posmic vs 34 anosmic; =6.48; P=.01); no significant dif- Trauma ferences were found between the frequencies of hyposmia and anosmia in group A (55 hyposmic vs 53 anosmic) or B (25 hyposmic vs 21 anosmic). In addition, the percent- SND age of patients with different causes of olfactory disorders was associated with the duration of the disease. That Figure 1. Olfactory loss among our patients was caused by upper respiratory is, URI olfactory disorders were most frequent in dura- tract infection (URI) (n=102; 36%), sinonasal disease (SND) (n=60; 21%), tion groups A (56%) and B (57%) and least frequent in trauma (n=47; 17%), congenital anosmia (n=9; 3%), and other causes group C (26%). The percentage of SND increased with in- (n=9; 3%). No cause for olfactory loss could be found in 51 patients (18%). creasing duration (group A, 5%; B, 9%; and C, 24%); similar findings were made for idiopathic olfactory loss (group Most of the patients also reported loss (150/231; 65%) A, 14%; B, 4%; and C, 30%) but not for trauma (group A, or alteration (33/231; 14%) of gustatory function. 22%; B, 26%; and C, 16%) or other causes (group A, 4%; B, 4%; and C, 4%). Accordingly, statistics revealed that the PERCENTAGE DECREASE OF QoL percentages of the 4 most frequent causes were significantly different when the duration of disease was shorter On average, patients reported a 20% decrease of QoL re- than 48 months (group A, ␹2=66.2 with PϽ.001; group lated to their olfactory loss. These figures differed with B, ␹2=32.3 with PϽ.001), but not when the duration of causes: patients with URI olfactory disorders (22%), SND disease was longer than 48 months. (27%), trauma (19%), idiopathic causes (13%), or other The percentage of women was found to be higher causes (13%) rated the loss of QoL to a similar degree (dif- in duration group A (64% women vs 36% men; ␹2=8.33; ferences NS). Patients with congenital anosmia indicated P=.004). In duration groups B and C, men and women no loss (0%) in QoL. No significant difference in QoL was were more equally distributed (group B, 44 women vs found across age groups, indicating that decreased QoL 57 men; group C, 46 women vs 54 men; NS). was not correlated with the duration of olfactory loss. Simi- larly, neither sex-related (women, 21% vs men, 19%) nor SELF-RATINGS OF OLFACTORY age-related differences (age group A, 24%; B, 21%; and C, AND GUSTATORY FUNCTION 15%) were seen in this measure of QoL. In hyposmic patients, the self-rated decrease of QoL exhibited a low co- Most of the examined patients fully completed the ques- efficient of correlation with the subject’s olfactory loss as tionnaire. From a total of 275 patients, 210 (76%) re- measured by the TDI score (r115=0.22; P=.02). ported loss of olfactory sensitivity and 210 patients (76%) reported altered sensitivity. Interestingly, although 11 DIFFICULTIES IN DAILY LIFE (4%) of the 275 patients reported normal olfactory sensitivity, after testing 5 of these 11 were diagnosed as func- Almost all patients reported difficulties in daily life due tionally anosmic, and the remaining 6 as hyposmic. These to their olfactory disorders. Specifically, 73% com- patients had been referred to the clinic by other otorhi- plained of difficulties with cooking, 68% of mood changes, nolaryngologists or by general practitioners who sus- 56% of decreased appetite, 50% of eating spoiled food, pected olfactory loss; some of them also came because 41% of too little perception of their own body odor, 30% relatives and/or spouses urged them to seek counseling. of burning food, and 8% of problems at work (Figure 3).

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©2002 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/30/2021 Table 2. Results for Butanol Odor Thresholds, Odor Discrimination, and Odor Identification in Patients With Functional Anosmia and Hyposmia, by Cause of Olfactory Loss*

Odor Threshold Odor Discrimination Odor Identification

Cause of Olfactory Loss 25 50 75 25 50 75 25 50 75 Anosmia Post-URI (n = 40) 1115 56578 SND(n=32)1134 67457 Posttraumatic (n = 32) 1115 67356 Idiopathic (n = 33) 1125 67457 Congenital (n = 9) 1114 56337 Other (n = 5) 11171011345 Hyposmia Post-URI (n = 62) 2357 8107810 SND(n=28)2357 8107910 Posttraumatic (n = 15) 2456 7107811 Idiopathic (n = 18) 34681011688 Congenital (n = 0) 0000 00000 Other (n = 4) 3462 71081111

*25, 50, and 75 indicate 25th, 50th (median), and 75th percentiles, respectively; URI, upper respiratory tract infection; and SND, sinonasal disease.

60 Whitney test) (Figure 4). Duration of disease had no sig- Age <41 y nificant effect on the complaint score (duration group Age 41-60 y A, 46%; B, 43%; and C, 46%). Similarly, the cause of the Age >60 y olfactory disorder had no significant effect (URI, 46%; SND, 53%; trauma, 47%; and idiopathic causes, 51%). Anosmic patients had a lower complaint score than hyposmic ones (anosmia, 45%; hyposmia, 52%; U=7881; 40 P=.01; Mann-Whitney test) (Figure 4); however, there was no significant difference between anosmia and hyposmia in QoL ratings (subjects with anosmia, 16%; subjects with hyposmia, 24%). In hyposmic patients, no significant correlation was found between the complaint % of Cases score and the patient’s ability to smell (TDI score). In addition, the complaint score and the self-rated QoL did 20 not correlate very well (r 242=0.18; P=.01). Patients who reported depressed mood as a conse- quence of olfactory loss had significantly higher complaint scores (depressed, 66%; nondepressed, 45%; U=964; PϽ.001; Mann-Whitney test) and higher self- ratings of loss of QoL (depressed, 44%; nondepressed,

0 29%; U=1824; P=.001; Mann-Whitney test). In con- SND Trauma Idiopathic URI trast, there was no significant difference between these Cause of Olfactory Loss 2 groups of patients regarding self-rated olfactory abili- Figure 2. The highest percentage of olfactory disorders related to upper ties (depressed, 22%; nondepressed, 22%) and TDI score respiratory tract infection (URI) was seen in older subjects. No significant (depressed, 16.2; nondepressed, 16.4). age-related differences were found for sinonasal disease (SND) or posttraumatic or idiopathic causes of olfactory loss. COMMENT These complaints were added to create a complaint score The present study addresses 2 major issues: (1) specific (percentage of complaints present); ie, presence of an in- characteristics of olfactory disorders as related to their dividual complaint was valued as “1”; absence of this com- causes and (2) the effects of olfactory disorders on daily plaint, “0.” The maximum complaint score (all com- life. Herein we discuss some of our more important plaints present) was 100%; the lowest score (no findings. complaints) was 0%. Both age and sex had a significant effect on diffi- DIFFERENT OLFACTORY SUBTESTS culties in daily life. Specifically, the youngest patients had DO NOT SEEM TO DIFFERENTIATE the highest degree of difficulties (age group A, 54%; B, BETWEEN CAUSES OF OLFACTORY LOSS ␹2 Ͻ 53%; C, 38% [ 2 = 24.6; P .001; Kruskal-Wallis test]) (Figure 4), and women mentioned more complaints than The present data indicate that causes of olfactory loss men (53% vs 42%, respectively; U=6751; PϽ.001; Mann- have no significant influence on results in odor thresh-

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75 75

50 50 Complaint Score, % % of All Patients

25 25

0 0 Work Burnt Body Rotten Appetite Mood Cooking <41 41-60>60 Men Women Anosmia Hyposmia Food Odor Food Age, y

Figure 3. Quality of life issues of patients with olfactory loss: cooking Figure 4. In the comparison of complaint scores in relation to age, sex, and indicates difficulties with cooking; mood, mood changes; appetite, decreased olfactory loss, the oldest patients had the lowest number of difficulties appetite; spoiled food, eating of spoiled food because of inability to smell (PϽ.001); women mentioned more complaints than men (PϽ.001); and spoilage; body odor, too little perception of own body odor; burnt food, anosmic patients had lower scores than hyposmic ones (P=.01). burning food while cooking because of inability to detect burning odor; and work, work-related problems. LIKELIHOOD OF RECOVERY DECREASES WITH INCREASING DURATION olds, discrimination, and identification. However, fur- OF OLFACTORY LOSS ther research in larger populations is needed to investigate whether the 3 tests of olfactory function differ in The presence of anosmia was found to increase as the du- their sensitivity to olfactory deficits in different age ration of the olfactory loss increased. This is consistent groups or in relation to the duration of the olfactory with reports that late recovery is relatively rare.12,13 loss. ELDERLY PATIENTS ARE PRONE PATIENTS MAY REPORT TO URI OLFACTORY LOSS NORMAL OLFACTORY FUNCTION IN THE PRESENCE OF ANOSMIA Consistent with other observations,9,14,15 we found that URI olfactory loss was more frequent in patients 65 years In the present study, 4% of the patients reported nor- or older, whereas all other causes were almost equally mal olfactory function despite the presence of olfac- distributed across the ages. In addition, an age-related tory deficit. This indicates once more6,7 that olfactory increase in the prevalence of olfactory loss has been re- testing is needed to properly evaluate patients’ olfac- ported.16 The same study indicated that olfactory dys- tory abilities. Recently, it has also been reported that function due to influenza and/or common colds and/or 42% of 203 patients were unable to correctly rate sinus infection correlated negatively with age. Because olfactory loss on a 4-point scale (normal, impaired but the authors evaluated olfactory loss in the context of URI not absent, no ability, highly sensitive).8 Thus, it and SND, this specific finding neither supports nor con- seems that a simple interview may provide entirely tradicts the present observations. This higher incidence misleading information. of URI olfactory loss in elderly persons may relate to the age-related decrease of the size of the olfactory epithe- INDICATIONS FOR lium,17,18 and thus to a higher vulnerability to the con- HIGHER RECOVERY RATE sequences of the infection. IN URI OLFACTORY LOSS DECREASE IN QoL MAY RELATE TO Among patients with URI olfactory loss, hyposmia was THE DEGREE OF OLFACTORY FUNCTION more common than anosmia. In addition, duration of ol- BEFORE LOSS OF OLFACTORY ABILITIES factory loss was found to be shorter in URI olfactory disorders than in SND-related or idiopathic olfactory dys- More than 70% of our population reported that the che- function. These findings may relate to the relatively high mosensory disorder interfered with their daily life activi- rate of recovery found in URI disorders.9-11 ties, including food preparation and intake. Both age and

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©2002 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/30/2021 sex had a significant effect on difficulties in daily life. Spe- did not differ in terms of their TDI scores. Here, it seems cifically, younger patients had more complaints than older possible that the difference between olfactory sensitiv- ones, and women had more than men. This may relate to ity prior to and after the loss of olfactory function might the relative loss of olfactory function, or, in other words, be the decisive factor in this correlation. In other words, to the degree of olfactory function before its loss. Specifi- the relative loss of olfactory function may relate to the cally, as olfactory function is best in the young5 and better development of a depressive state.24,25 in women than in men,19 these initially more sensitive Lifetime prevalence for any psychiatric morbidity groups are more likely to have the most complaints when ranges from 21% to 65%, and depression is among the olfactory function is impaired. The higher significance of most common. It has been reported that 28% of patients olfactory loss in relation to sex may also be a factor in the with olfactory dysfunction have a feeling of vulnerabil- shorter duration of olfactory loss in women than in men. ity because they have difficulties detecting spoiled foods, That is, women seem to find olfactory problems more dis- smoke, gas, or body odors.22 As many as 26% of patients turbing and thus may seek counseling sooner than men. with olfactory dysfunction even reported disruption of In terms of self-reported changes of quality of life, their marital, sexual, and social relationships in relation 42% of our population indicated a decrease in QoL of more to their olfactory loss.20 In addition, in a study using the than 10%. In comparison, it has been reported that 82% Beck Depression Inventory and the revised symptom of subjects with hearing loss indicated a decreased QoL20; checklist 90, at least 17% of patients with olfactory loss 24% of patients with hearing loss were reported to be de- suffered from moderate depression.22 pressed.21 In this context it should also be mentioned that our population is certainly nonrepresentative of all people OLFACTORY LOSS SEEMS TO PRODUCE with olfactory loss. Most of our patients report a high ol- FEW WORK-RELATED PROBLEMS factory sensitivity prior to loss of olfactory function. Thus, it may well be that patients with a lower degree of olfac- A relatively small number of patients indicated that prob- tory acuity prior to loss may not even seek counseling. lems of olfaction interfered with their occupations. This might be because (1) older patients were usually re- DECREASE OF QoL DOES NOT CHANGE tired, and (2) our population did not include many pa- WITH DURATION OF OLFACTORY LOSS tients professionally involved in the analysis of odors (eg, the food or chemical industries). On the other hand, one Duration of olfactory loss did not seem to affect self- would like to think that, for example, electricians would rated changes in QoL. This result emphasizes the sig- need to know when and where cables burn or car me- nificance of smells for everyday life; it also indicates that chanics would need to know whether this clear liquid various coping strategies may be insufficient to deal with was water or gasoline.22 While the present observations this loss of olfactory-mediated sensations.22 may be used as an argument in the discussion regarding the relatively small financial compensation of olfactory COMPLAINT SCORES SEEM TO BE HIGHER loss in legal cases, one must not forget specific profes- IN HYPOSMIA THAN IN ANOSMIA sions that strongly rely on an intact sense of smell (eg, perfumers or chefs). In the present study, hyposmic patients had higher complaint scores than anosmic patients. What would explain OLFACTORY LOSS SEEMS TO PRODUCE this anomalous finding? One explanation may relate to the MOSTLY FOOD-RELATED PROBLEMS reinforcing character of the occasional perception of odors in hyposmia. It may serve as a constant reminder of the Food preparation and intake was a major problem in our olfactory loss, like an echo from an olfactory world that, population. Flavor is a complex interaction of smell, taste, although present, cannot be perceived. Similar findings pH, temperature, texture, and sensitivity of the oral cav- were reported elsewhere with regard to behavior of pa- ity. However, patients often associate flavor with the sense tients with anosmia and hyposmia in an odor identifica- of taste only. Most patients with olfactory loss experi- tion test.23 When looking at the effort different groups of ence the loss of flavor as a loss of taste and thus confuse patients took to release an odor in a “scratch and sniff test,” olfactory and gustatory abilities.6 researchers found that hyposmic patients scratch much Some authors provide evidence olfactory dysfunc- harder than healthy controls. In contrast, anosmic pa- tion does not lead to nutritional problems.26 When in- tients seem to be frustrated after only a few trials and scratch terviewed about food preferences, only 24% of anosmic significantly less than hyposmic patients. Other explana- patients reported unchanged preferences.27 Many anos- tions may relate to the questionnaire itself; ie, the out- mic patients also reported that they forget about the need come might have been different if questions were put dif- to eat. Others reported weight loss (7%); still others re- ferently. This will be subject to further research. ported weight gain (14%).28 This is consistent with our own experiences with anosmic patients who complain SELF-RATED DEPRESSION of weight gain; that is, after having lost the most sophis- SEEMINGLY DOES NOT RELATE TO ticated sense to enjoy foods, some patients with anos- MEASURED OLFACTORY FUNCTION mia simply eat more sweet dishes to reward themselves after an uninteresting dinner. Patients reporting to be depressed had higher com- Olfactory loss produces numerous complaints. It se- plaint scores and higher self-reported loss of QoL, but verely affects the lives of patients who report to special-

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©2002 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/30/2021 ized centers. This clearly indicates the need for an in- 10. Mott AE, Leopold DA. Update in otolaryngology, I: disorders in taste and smell. creased research effort in the treatment of olfactory loss. Med Clin North Am. 1991;75:1321-1353. 11. Duncan H. Postviral olfactory loss. In: Seiden AM, ed. Taste and Smell Disor- ders. New York, NY: Thieme; 1997:72-78. Accepted for publication November 16, 2001. 12. Hendriks APJ. Olfactory dysfunction. Rhinology. 1988;26:229-251. We thank Kati Rosenheim and S. Pabinger for their help 13. Duncan HJ, Smith DV. Clinical disorders of olfaction. In: Doty RL, ed. Hand- in acquisition of the data; Ebba He´den-Blomqvist, MD, for book of Olfaction and Gustation. New York, NY: Marcel Dekker; 1995:345- 365. her thoughtful comments on the manuscript; and Elisabeth 14. Goodspeed RB, Gent JF, Catalanotto FA. Chemosensory dysfunction. 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